The invention relates to a prosthetic device, and more particularly to a stump boot for an ankle disarticulation patient, or Syme's amputation, for eliminating the build up of scare tissue and callous formation in said stump boot wearer.
The Syme technique of amputation has existed since 1842. Named after James Syme, and referred to as a disarticulation at the ankle, the surgical amputation at the ankle involves removal of the malleoli and forward rotation of the heel pad over the end of the residual tibia. The disarticulation is performed through the ankle joint with preservation on the heel pad to permit weight-bearing at the end of the stump. The ankle joint consists of three bones including the tibia which forms the inside, or medial, portion of the ankle, the fibula which forms the lateral, or outside portion of the ankle, and the talus underneath. The ankle joint is responsible for up and down motion of the foot. The Syme's amputation cuts through the ankle joint while maintaining the tough, durable skin of the heel pad. The heel pad must be intact and accurately applied as it is crucial for weight-bearing and protecting the cut surface of the tibia and fibula. The Syme's amputee continues to bear weight in the residual foot while experiencing sensation and proprioception, the ability to feel position and surface.
The Syme's amputation is mainly used for foot deformities, which cannot be corrected to a plantigrade position, fibular hemimelia and severe foot injury, as long as the heel pad remains intact, vascular insufficiency, with or without diabetes, and for infections of the forefoot. The process for a Syme's amputation must be exact in order to provide the amputee with the greatest benefits.
The significant outcome of Syme's technique for those wearing a prostheses, is that the patient has a foundation to walk on instead of cutting off the entire leg. However, surgeons are reluctant to perform the operation. The cause of the hesitancy is centered around the manufacture and use of the prosthesis fitted afterward. In fact, the most common problem with lower limb amputations is prosthetic fittings. The Syme's amputee is left with an end bearing stump that requires the use of a prosthesis when walking to prevent the heel pad from losing its essential position. The prosthesis used must accommodate the flair of the distal tibial metaphysic that is covered with heavy plantar skin and thus is rather large and bulky. For this reason the amputation is usually not recommended for women. Additionally, painful neuroma and impairment of the blood supply can result when dressings are applied too tightly to a Syme's amputee. Sometimes, swelling occurs beneath adhesive strappings that are not removed soon enough.
In the Syme's amputation the resulting stump tissue that is preserved is constructed by nature to bear weight and to deliver sensory feedback from walking. Since the stump has more surface area and the leg has a longer lever arm, the amputee has considerable enhanced control of their leg movements.
Typical prosthesis devices are self-suspending and therefore there is little or no positioning of the prosthesis during the transition from swing phase to stance phase. However, there are many obstacles involved in properly fitting the prosthetic device. Not only must the prosthesis fit comfortably, but heat and perspiration must also be considered. The intricate process of making the device, the difficulty of fitting the device, and the frequent structural failures and poor cosmesis must all be taken into consideration. In addition, the stump is often tender on weight-bearing and results in callous formation.
The stump boot of the present invention eliminates complications associated with prosthetic devices and allows patients, both male and female, to receive mobility and independence not otherwise afforded.
Prosthetic devices are generally known in the art. U.S. Pat. Nos. 5,317,819 and 5,544,429 to Ellis, III both disclose an athletic shoe having a sole that conforms to the natural shape of the foot, particularly the sides, and that has a constant thickness in frontal plane cross sections. The thickness of the shoe sole side contour equals and therefore varies exactly as the thickness of the load-bearing sole portion varies due to heel lift, for example. U.S. Pat. No. 6,115,945 also to Ellis III discloses an athletic shoe having a sole that conforms to the natural shape of the foot, including a bottom and sides when the foot sole deforms naturally by flattening under load while walking or running in order to provide a stable support base for the foot and ankle. Deformation sipes such as slits or channels are introduced in the shoe sole along its axis, and other axes, to provide it with flexibility roughly equivalent to that of the foot. The result is a shoe sole that accurately parallels the frontal plane deformation of the foot sole, which create a stable base that is wide and flat even when tilted sideways in extreme pronation or supination motion.
U.S. Pat. No. 5,797,862 to Lamount discloses a protective boot for patients with arterial disease having an insole formed with a heat activated material to form a permanent impression of the bottom of a patient's foot.
U.S. Pat. No. 6,470,599 to Chu discloses a climbing shoe having an inner sole, an outer sole and a molded middle sole between the inner and outer sole. The middle sole is concave in shape. The outer sole conforms to the concave shape of the middle sole. The concave shape allows the outer sole to hook on a rocky ledge. The molded middle sole provides a structure that causes the concave outer sole to substantially maintain the concave shape when pressure is applied to the outer sole.
U.S. Pat. No. 5,224,810 to Pitkin discloses an athletic shoe providing a safe orientation of the foot during an immediate stop in the medial lateral direction and to preclude hyperinversion of the foot in the subtalar joint.
U.S. Pat. No. 5,154,682 to Kellerman discloses a low friction shoe insert of ultrahigh molecular weight polyethylene or the like having a coefficient of friction of 0.3 or less with an array of detachable discrete cushion elements on the shoe contacting lower surface to both frictionally anchor the insert to the shoe and permit the shape to be customized to the wearer's foot and selectively relieve pressure on painful and sensitive areas.
U.S. Pat. No. 5,019,064 to Eilender discloses a multilayer low friction pad for reducing shear and friction forces on a person's body, and for preventing and treating sores on a person's body caused by shear forces, friction, pressure, chafing and moisture.
U.S. Pat. No. 6,362,387 to Carlson et al., discloses a patch of low friction materials, such as a film of polytetrafluoroethylene sized to provide an area of low friction support for a portion of a human body relative to an object such as a shoe or prosthetic socket. The patch can be lined with foam, or preferably, a stretch fabric so that it will fit around irregular contours of the shoe, socket, or the skin itself. The patches reduce shear trauma in critical load areas. After identifying regions of high loads, the method comprises applying the patches as needed to avoid sores, calluses, blisters and abrasions.
U.S. Pat. No. 6,514,293 to Jang et al. discloses a prosthetic foot that is to be connected to a pylon that is utilized for the substitution of the shinbone of an amputee.
U.S. Pat. No. 5,695,526 to Wilson discloses a one-piece mechanically differentiated prosthetic foot and associated ankle joint with Syme modification.
U.S. Pat. No. 6,811,571 to Phillips discloses a cushioned ankle prosthetic foot and a cosmesis having a slot between the big toe and adjacent toe to allow the amputee to wear thong sandals and the like. U.S. Pat. Nos. 5,993,488 and 5,800,569 to Phillips disclose prosthesis with resilient ankle block. U.S. Pat. No. 5,728,177 also to Phillips discloses a prosthesis with foam block ankle. U.S. Pat. No. 5,549,714 also to Phillips discloses a Symes foot prosthesis. U.S. Pat. No. 5,376,141 also to Phillips discloses a low-profile Syme's foot prosthesis.
U.S. Pat. No. 6,406,499 to Kania discloses an annular sleeve configured to receive a limb and having a gel composition containing a block copolymer and mineral oil. U.S. Pat. No. 5,653,768 also to Kania discloses a dual cantilevered leaf spring structure for providing a prosthesis for an amputee.
U.S. Pat. No. 4,225,982 to Cochrane et al. discloses a molded Syme foot with attached stump socket having a flexible pre-cast foot comprising a hollow flexible slipper member which has a rounded heel contour and keel cavity.
U.S. Pat. No. 5,545,230 to Kinsinger et al. discloses a prosthesis mounting adapter and method. U.S. Pat. No. 6,261,324 to Merlette discloses a foot prosthesis. U.S. Pat. No. 5,030,239 to Copes discloses a biomechanical ankle. U.S. Pat. No. 4,923,476 to Cooper et al. discloses an alignment device and method of artificial limb manufacture. U.S. Pat. No. 6,562,075 to Townsend et al. discloses a prosthetic foot with tunable performance.
While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter.